I think Schmidt probably could have phrased it better, but I don't think he was being racist. A plyer who wants to be a leader on a team probably does need to be able to communicate with the rest of the team, no matter what their native tongue is. If I ran a baseball academy in a Latin American country, I'd have mandatory English classes. All else being equal, an English speaker is going to have an easier time making it in baseball than one who doesn't speak English.
I don't have an issue with an interpreter going to the mound, as long as all that person does is translate and not offer instruction or give his opinion.